Lolium perenne cv. Nui is a cultivar of ryegrass grown throughout New Zealand in pastures due to favourable traits such as high palatability for livestock and its ability to withstand intensive grazing. However, the productivity of pastures is reduced when levels of aluminium and other metals accumulate in soils to toxic levels, a phenomenon referred to as the ‘acid soil syndrome’. In response to this toxicity, plants activate a series of antioxidant reactions, with one catalysed by the superoxide dismutase (SOD) enzymatic system. The enzyme system comprises three isoenzymes, a Cu/ZnSOD, FeSOD and a MnSOD which catalyse the same reaction but differ in amino acid sequence, molecular mass and the metal ion co-factor (hence Cu/ZnSOD, FeSOD and MnSOD). Together these isoenzymes combat the damaging effect of superoxide radicals which accumulate due to metal toxicity. In this thesis, the isolation of genes encoding isoenzymes of the SOD enzyme from L. perenne cv. Nui is described. As well, the growth of L. perenne cv. Nui and changes in expression of the SOD genes encoding each isoenzyme in response to aluminium treatment (0.2mM AlCl3) is investigated. A 1072 bp FeSOD gene sequence and a 705 bp MnSOD gene sequence were isolated from shoot tissue of L. perenne cv. Nui using a combination of RT-PCR with degenerate primers and 3'-RACE. The FeSOD gene comprised 572 bp of the coding sequence and 500 bp of 3'-UTR while the MnSOD gene comprised 508 bp of coding sequence and a 197 bp 3'-UTR. By alignment of each sequence with the gene from the database with highest identity it was predicted that the translation start codon (ATG) is located a further 196 bp upstream for the FeSOD gene (aligned with an Oryza sativa FeSOD sequence as a reference) and a further 152 bp upstream for the MnSOD sequence (aligned with a Triticum aestivum MnSOD sequence as a reference). Using RT-PCR with degenerate primers, a 313 bp CuSOD sequence was predominantly cloned from shoot tissue of L. perenne cv. Nui, but it was not possible to generate the 3'-UTR using 3'-RACE. For growth analysis, seedlings of L. perenne cv. Nui were germinated and acclimatised in Hoagland’s solution, and then subjected to either aluminium treatment (0.2mM AlCl3) or no treatment to act as a control over a designated time course of 0, 4, 8, or 24 hours. Two growth trials were conducted that differed in the age of seedlings used and plant tissues were separated into root and shoot tissues. Similar growth trends were observed in both trials, but the sampling regime in the second growth trial meant that statistical analysis could be carried out. In this trial, analysis revealed that over a time course of 24 hours exposure to 0.2mM aluminium, both root and shoot tissue fresh weight did not significantly differ when compared to the control (no aluminium). A general trend of an increase in root and shoot fresh weight was observed in plants treated with aluminium, but this trend was not significant at P=0.05. No significant change in fresh weight partitioning from shoot to root, or root to shoot in response to aluminium was also observed. Using semi-quantitative Reverse Transcriptase-Polymerase Chain Reaction (sqRTPCR) and primers based around the 3'-UTR with RNA isolated from plants grown in the second hydroponic trial, it was determined that under the conditions used, expression of the FeSOD and MnSOD genes isolated in this study were neither up-regulated or downregulated in response to aluminium treatment in both shoot and root tissue. Further, using degenerate primers to detect expression of one or more genes encoding the Cu/ZnSOD isoenzyme, total expression of the Cu/ZnSOD isoenzyme was also unresponsive to aluminium treatment.

Appendix content (raw data and statistics; sequences) unavailable online, but available with print copy / Epichloë/Neotyphodium endophytes are a group of clavicipitaceous fungi that form symbiotic associations with temperate grasses. The asexual N. lolii form asymptomatic mutualistic associations with ryegrass whereas the sexual E. typhina behaves similar to a mutualist during the vegetative phase of plant growth but switches to epiphytic growth and formation of an external stroma upon development of the floral inflorescence. The aim of this project was to study the metabolic interaction between these endophytes and their perennial ryegrass host. The role of endophyte thiamine biosynthesis in host colonisation and stroma development was chosen, because of the key role this coenzyme plays in primary cellular metabolism and because thiamine biosynthetic genes are induced in several fungal-plant interactions. The orthologue (thil) of Saccharomyces cerevisiae THI4 was isolated from N. lolii and E. typhina by PCR using degenerate primers designed to conserved regions of known thiazole biosynthetic genes. This gene is expressed in planta and in culture, and is alternatively spliced, with distinct patterns of the isoforms expressed under different nutritional conditions. Mutant with a deletion in the E. typhina thil gene was constructed and shown to have reduced hyphal density and branching compared to the wild-type on defined media lacking thiamine. Both thiamine and thiazole complemented this defect. Artificial inoculation of the mutants into plants showed that the thil mutant retained the ability to colonise the perennial ryegrass host and form stromata. However, the mutant had some differences in host colonisation and growth, including reduced hyphal branching and reduced detrimental effects on the host. In addition, glycogen-like deposits, which were abundant in the wild-type hyphae, were not evident in the mutants. Unexpectedly, both the thil mutant and wild-type strains formed some stromata on vegetative tissue. Electron microscopic examination revealed that the cells of epiphytic hyphae found on the vegetative tillers typically were enlarged, lacking in cytoplasm and highly vacuolated, an ultrastructure similar to that found for hyphae growing in reproductive tillers. The mutants retained the ability to form conidia on the outer layer of the stromata. Extensive vascular colonisation and hyphal ramification in the mesophyll were common characteristics of stromata bearing regions. Although the morphology and ultrastructure of stromata formed on vegetative tillers is very similar to those on reproductive tillers, one significant difference was the presence of abundant glycogen-like deposits in hyphae of vegetative tillers. Furthermore, there were dramatic differences in the levels of glycogen-like deposits in hyphae in different regions of the vegetative tillers, indicating that the energy demand changes during stroma development. This is the first report of E. typhina forming stromata on non-inflorescence tillers.

The topic of the thesis: Comparison of the seed and biomass yields of breeding vegetation cover This thesis was focused on yield ability of the selected ryegrass species grown in the Czech Republic. Experimental fields were based on the land of private working farmer Mr. Pavel Mimra in Slatina u Vysokého Mýta. There were grown three species of ryegrass on the farm in vegetational period of 2013/2014. Monitoring was primarily focused on the formation of yield aspects - the number of the ears, the number of the grains in the ear and the weight of thousand grains. In the vegetational period was also monitored presence of weeds, pests and diseasases and was evaluated total amount of plants and their offsets. The total amount and subsequent use of remaining biomass from breeding covers was also monitored. In the end, there were discovered results compared with theoretical yield. Costs, profits and economical relevance were evaluated in the final part of thesis

O experimento conduzido na Fazenda Rancho Santa Zelina, em Júlio de Castilhos, RS, entre julho de 2014 a setembro de 2015, analisou o desempenho reprodutivo de 42 vacas mestiças Angus primíparas aos 24/25 meses de idade postas no pós-parto em pastagem cultivada de aveia (Avena strigosa Schreb) e azevém (Lolium multiflorum Lam.). Aos 80 dias pós-parto foram distribuídas conforme peso (PC) e escore de condição corporal (ECC) em dois sistemas alimentares: SS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural; CS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural com a suplementação diária de 0,8% do PC de suplemento contendo 14% proteína bruta (PB) e 70% de nutrientes digestíveis totais (NDT). O método de pastoreio foi o contínuo com massa de forragem (MF) média de 1450 kg/ha de matéria seca (MS) em pastagem cultivada e 2150 kg/ha/MS em pastagem natural. O delineamento experimental foi o inteiramente casualizado, com dois sistemas alimentares e vinte e uma vacas por sistema alimentar, sendo cada vaca considerada uma unidade experimental. Para comparar os sistemas alimentares, as variáveis que apresentaram normalidade foram avaliadas utilizando o procedimento MIXED do SAS. A variável taxa de prenhez foi avaliada pelo teste do qui-quadrado. A suplementação não influenciou o peso (PCFT) e condição corporal final (ECCFT) das vacas, porém a variação de peso diária média das vacas do CS foi superior a das em SS durante os sistemas alimentares (0,465 kg e 0,227 kg, respectivamente). Os bezerros do CS nesse período apresentaram maior ganho médio diário, 0,829 kg comparado com aqueles do SS de 0,644 kg e maior peso final (130,86 kg e 117,29 kg, respectivamente). As vacas do CS tiveram a significativa maior taxa de prenhez de 80,95%, enquanto as do SS tiveram 57,14%. Aos 42 dias de acasalamento 80,95% das vacas do CS estavam prenhes, enquanto do SS apenas 28,57% já tinham concebido. Vacas primíparas aos 24 meses de idade e que irão conceber têm maior peso e escore de condição corporal ao início do acasalamento do que as futuras falhadas. / The experiment was conducted at the Farm Rancho Santa Zelina in Julio de Castilhos, RS, from July 2014 to September 2015, examined the reproductive performance of 42 crossbred cows Angus gilts to 24/25 months old put postpartum in cultivated pasture oat (Avena strigosa Schreb) and ryegrass (Lolium multiflorum Lam.). After 80 days postpartum were distributed as weight (BW) and body condition score (BCS) in two food systems:SS – 23 days in a cultivated pasture (Avena strigosa Schreb. e Lolium multiflorum Lam.) and 7 days in a natural grassland; CS – 23 days in the same cultivated pasture and 7 days in a natural grassland receiving 0,8% BW supplement with 14% crude protein (CP) and 70% total digestible nutrients (TDN). The grazing method was continuous with herbage mass (MF) average of 1450 kg/ha of dry matter (DM) in cultivated pasture and 2150 kg/ha/DM in natural pasture. Treatments were arranged in a completely randomized design with two food systems and twenty-one cows for feeding system, where each cow was considered an experimental unit. To compare the food systems, variables with normal distribuition were assessed using the SAS MIXED procedure. The pregnancy rate was evaluated using the chi-square test. Supplementation did not affect cows‟ final body weight (FBW) and final body condition (FBC), but the daily average weight variation of cows in CS was higher than in SS (0.465 kg and 0.227 kg, respectively). The CS calves this period had higher average daily gain, 0.829 kg compared to those of the SS 0.644 kg and higher final weight (130.86 kg and 117.29 kg, respectively). The 80.95% pregnancy rate of the CS cows was higher than the 57.14 % of SS cows. After 42 days of mating, 80.95% of the CS primiparous cows had conceived, against just 28.57% from the SS. Primiparous cows at 24/25 months old and that will get pregnant have higher BW and BCS at beginning of the mating than the open ones.

Objetivo: determinar la influencia de la utilización de sedimentos de piscigranja sobre la disponibilidad de arsénico y crecimiento de ryegrass (Lolium perenne) en un suelo contaminado con arsénico, del distrito de El Mantaro, Jauja. 2016. Método: se utilizó el método de análisis: las muestras de suelo del distrito El Mantaro, fueron analizadas en sus propiedades físico-químicas: densidad aparente, pH, conductividad eléctrica, contenido de nutrientes y materia orgánica. Las técnicas utilizadas son estándar para cada tipo de determinación. Una vez reportados los análisis se interpretaron los datos para determinar sus niveles, según el tipo de análisis. Diseño: se utilizó una muestra de suelo compuesta de la capa arable, y se distribuyó en macetas de 2 kg de capacidad, donde se aplicó cinco dosis de SP (0%, 2%, 4%, 6% y 8%), cuyos tratamientos estuvieron dispuestos en un diseño experimental completamente al azar. Resultados: las dosis de sedimentos de piscigranja, disminuyen la disponibilidad de este metaloide a valores inferiores al estándar (<12 mg/kg), en el rango de 9,07 mg/kg a 7,120 mg/kg, debido a la adsorción en la fase sólida del suelo, representando porcentajes de disminución de disponibilidad entre 1,726% a 23,169% respecto al testigo; sobresale la dosis de 8% de sedimentos de piscigranja, que redujo la disponibilidad de arsénico del suelo en 23,168%. Las dosis de sedimentos de piscigranja incrementaron significativamente el crecimiento de ryegrass, en altura de planta entre 79,556% y 91,66%; en materia seca de la parte aérea entre 81,231% y 198,462%, y en materia seca de raíz entre 186,667% y 346,667%; atribuible a la mejora de las propiedades del suelo, y por ende la influencia en el crecimiento de ryegrass.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was carried out in order to evaluate the milk yield and composition from ewes of two genetic groups, as well as the influence of milk yield on performance, carcass characteristics and live weight components of nursling lambs maintained exclusively on ryegrass pasture (Lolium multiflorum LAM.). It was evaluated twelve Texel x Ile de France crossbred ewes (beef crossbred ewes) and twelve Texel (1/4) x Ile de France (1/4) x Lacaune (1/2) ewes (dairy crossbred ewes). It was included in this study only single delivered lamb and their mothers, totalizing 24 lambs from the same Sulffolk ram. The animals (ewes and lambs) were maintained throughout the experimental period in annual ryegrass in continuous grazing system with variable stocking rate. The estimation of milk yield was performed weekly. Milk samples were collected for laboratory analysis of protein, fat, density, acidity and lactose. There was a difference (P<0.05) among genotypes for milk yield (g/day), with a quadratic effect over time. Milk composition variables were not affected by treatments. The lambs were slaughtered when reaching 28 kg body weight. There was no effect (P>0.05) of the genotype of the lambs neither to the average daily weight gain nor to slaughter age. Also, there was no effect of genotype (P<0.05) on farm weight, body condition and leg length. Concerning carcass traits, only the empty body weight was affected by treatments. The gastrointestinal tract was higher (P<0.05) for lamb sons of beef crossbred ewes. Therefore, it can be inferred that the higher milk production by dairy crossbred ewes did not influence the carcass of their lambs, but induces a slower development of gastrointestinal tract of these animals comparing to lambs from the beef crossbred ewes. / O objetivo deste estudo foi avaliar a produção e a composição centesimal do leite de ovelhas de diferentes grupamentos genéticos, assim com a influência da produção de leite no desempenho, características de carcaça e componentes do peso vivo de cordeiros lactentes mantidos exclusivamente em pastagem de azevém anual (Lolium multiflorum LAM.). Avaliaram-se 12 ovelhas do cruzamento alternado entre as raças Texel x Ile de France e 12 ovelhas F1 provenientes do cruzamento entre as raças Texel x Ile de France (!) x Lacaune (!). Em ambos os tratamentos as fêmeas eram paridas de cordeiros simples, totalizando 24 cordeiros de cruzamento industrial, machos não castrados e fêmeas, filhos de reprodutor da raça Suffolk. Os animais (ovelha + cordeiro) permaneceram durante todo o período experimental em pastagem cultivada de azevém anual, em sistema de pastejo contínuo com lotação variável. A estimativa da produção de leite foi realizada semanalmente. Amostras do leite foram coletadas para análises laboratoriais dos teores de proteína, gordura, densidade, lactose e acidez. Foi observada diferença (P<0,05) entre os genótipos para a produção de leite (g/dia), demonstrando um comportamento quadrático. Para as variáveis da composição do leite não foi encontrada diferença entre os tratamentos. Os cordeiros foram abatidos ao atingir 28 kg de peso corporal em jejum. Não houve efeito (P>0,05) do genótipo dos cordeiros para o ganho de peso médio diário e nem para idade ao abate. Nas características corporais in vivo houve diferença entre os tratamentos (P<0,05) para o peso vivo de fazenda, condição corporal e comprimento de posterior. Quanto as características de carcaça, somente o peso de corpo vazio diferiu entre os tratamentos. O trato gastro-intestinal foi maior (P<0,05) para os cordeiros filhos das ovelhas cruza carne. Pode-se inferir que a maior produção de leite pelas ovelhas cruza leite não influenciou nos rendimentos de carcaça de seus cordeiros, mas sim no desenvolvimento mais lento do trato gastro-intestinal destes animais em relação ao cordeiros provenientes das ovelhas cruza carne.

O experimento conduzido na Fazenda Rancho Santa Zelina, em Júlio de Castilhos, RS, entre julho de 2014 a setembro de 2015, analisou o desempenho reprodutivo de 42 vacas mestiças Angus primíparas aos 24/25 meses de idade postas no pós-parto em pastagem cultivada de aveia (Avena strigosa Schreb) e azevém (Lolium multiflorum Lam.). Aos 80 dias pós-parto foram distribuídas conforme peso (PC) e escore de condição corporal (ECC) em dois sistemas alimentares: SS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural; CS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural com a suplementação diária de 0,8% do PC de suplemento contendo 14% proteína bruta (PB) e 70% de nutrientes digestíveis totais (NDT). O método de pastoreio foi o contínuo com massa de forragem (MF) média de 1450 kg/ha de matéria seca (MS) em pastagem cultivada e 2150 kg/ha/MS em pastagem natural. O delineamento experimental foi o inteiramente casualizado, com dois sistemas alimentares e vinte e uma vacas por sistema alimentar, sendo cada vaca considerada uma unidade experimental. Para comparar os sistemas alimentares, as variáveis que apresentaram normalidade foram avaliadas utilizando o procedimento MIXED do SAS. A variável taxa de prenhez foi avaliada pelo teste do qui-quadrado. A suplementação não influenciou o peso (PCFT) e condição corporal final (ECCFT) das vacas, porém a variação de peso diária média das vacas do CS foi superior a das em SS durante os sistemas alimentares (0,465 kg e 0,227 kg, respectivamente). Os bezerros do CS nesse período apresentaram maior ganho médio diário, 0,829 kg comparado com aqueles do SS de 0,644 kg e maior peso final (130,86 kg e 117,29 kg, respectivamente). As vacas do CS tiveram a significativa maior taxa de prenhez de 80,95%, enquanto as do SS tiveram 57,14%. Aos 42 dias de acasalamento 80,95% das vacas do CS estavam prenhes, enquanto do SS apenas 28,57% já tinham concebido. Vacas primíparas aos 24 meses de idade e que irão conceber têm maior peso e escore de condição corporal ao início do acasalamento do que as futuras falhadas. / The experiment was conducted at the Farm Rancho Santa Zelina in Julio de Castilhos, RS, from July 2014 to September 2015, examined the reproductive performance of 42 crossbred cows Angus gilts to 24/25 months old put postpartum in cultivated pasture oat (Avena strigosa Schreb) and ryegrass (Lolium multiflorum Lam.). After 80 days postpartum were distributed as weight (BW) and body condition score (BCS) in two food systems:SS – 23 days in a cultivated pasture (Avena strigosa Schreb. e Lolium multiflorum Lam.) and 7 days in a natural grassland; CS – 23 days in the same cultivated pasture and 7 days in a natural grassland receiving 0,8% BW supplement with 14% crude protein (CP) and 70% total digestible nutrients (TDN). The grazing method was continuous with herbage mass (MF) average of 1450 kg/ha of dry matter (DM) in cultivated pasture and 2150 kg/ha/DM in natural pasture. Treatments were arranged in a completely randomized design with two food systems and twenty-one cows for feeding system, where each cow was considered an experimental unit. To compare the food systems, variables with normal distribuition were assessed using the SAS MIXED procedure. The pregnancy rate was evaluated using the chi-square test. Supplementation did not affect cows‟ final body weight (FBW) and final body condition (FBC), but the daily average weight variation of cows in CS was higher than in SS (0.465 kg and 0.227 kg, respectively). The CS calves this period had higher average daily gain, 0.829 kg compared to those of the SS 0.644 kg and higher final weight (130.86 kg and 117.29 kg, respectively). The 80.95% pregnancy rate of the CS cows was higher than the 57.14 % of SS cows. After 42 days of mating, 80.95% of the CS primiparous cows had conceived, against just 28.57% from the SS. Primiparous cows at 24/25 months old and that will get pregnant have higher BW and BCS at beginning of the mating than the open ones.

Made available in DSpace on 2014-08-20T14:07:35Z (GMT). No. of bitstreams: 1 dissertacao_diego_severo_fraga.pdf: 981696 bytes, checksum: 8402f7a17f38638a74dfdc1e8398594d (MD5) Previous issue date: 2012-03-02 / Ryegrass is an annual cycle weed, found in virtually all winter crops, orchards and vineyards of Southern Brazil. The species is usually controlled by glyphosate, however, continued use of the product selected resistant biotypes. The managing with acetyl Coenzime A carboxylase (ACCase) enzyme inhibiting herbicides is the main alternative to control these species, which has not been satisfactory in some places, causing suspicion of being selected biotypes that are resistant to this herbicide group. The objective of this research was to evaluate the distribution of ryegrass biotypes resistant to ACCase enzyme inhibitors herbicides in Rio Grande do Sul (RS); assess by means of dose-response curves ryegrass biotypes resistant and susceptible to the herbicide fluazifop; estimate the fitness cost of susceptible and resistant biotype to fluazifop, and to investigate the competitive ability of these biotypes among themselves and with the wheat crop. Thus, seeds of ryegrass plants that survived applications of ACCase enzyme inhibitors were collected from farms in Northern RS, comprising 80 towns. The results showed that there were ryegrass resistant biotypes to the herbicide fluazifop when applied at the maximum dose of 125g a.i.ha-1 and stage specified by the manufacturer. Ryegrass biotypes have different levels of herbicide resistance, and the biotype of ryegrass TUC 11 has low-level resistance to the herbicide fluazifop. In the assessment of competitive ability and fitness cost it was found that the susceptible ryegrass and low level resistance, in general, have similar values for these variables. Wheat cultivar FUNDACEP Horizonte, in general, showed greater competitive ability than the low level resistance biotype and equivalent to the susceptible. / O azevém é uma planta daninha de ciclo anual, encontrada em praticamente todas as lavouras de inverno, em pomares e vinhedos da região Sul do Brasil. A espécie é normalmente controlada pelo herbicida glyphosate, no entanto, o uso continuado desse produto selecionou biótipos resistentes. O manejo com herbicidas inibidores da enzima acetil Coenzima A carboxilase (ACCase) é a principal alternativa para o controle dessas espécies, o qual não tem sido satisfatório em alguns locais, provocando a suspeita de que estejam sendo selecionados biótipos resistentes a este grupo de herbicidas. Assim, o objetivo da pesquisa foi avaliar a distribuição dos biótipos de azevém resistentes aos herbicidas inibidores da enzima ACCase no Rio Grande do Sul (RS); avaliar, por meio de curvas de dose-resposta, biótipos de azevém resistente e suscetível ao herbicida fluazifop; estimar o valor adaptativo de biótipo suscetível e resistente ao fluazifop; e, investigar a habilidade competitiva desses biótipos entre si e com a cultura do trigo. Para isso, sementes de plantas de azevém que sobreviveram a aplicações de inibidores da enzima ACCase foram coletadas em lavouras na região norte do RS, totalizando 80 municípios. Os resultados demonstraram que existem biótipos de azevém resistentes ao herbicida fluazifop quando aplicado na dose máxima de 125g i.a.ha-1 e estádio indicado pelo fabricante. Os biótipos de azevém apresentam diferentes níveis de resistência ao herbicida, sendo que o biótipo de azevém TUC 11 apresenta resistência de nível baixo ao herbicida fluazifop. Na avaliação de habilidade competitiva e valor adaptativo verificou-se que os biótipos de azevém suscetível e com resistência de nível baixo, em geral, apresentam valores similares para estas variáveis. A cultura do trigo, cultivar FUNDACEP Horizonte, em geral, apresentou maior habilidade competitiva que o biótipo com nível baixo de resistência e equivalente ao suscetível.

Master of Science / Department of Agronomy / Randall S. Currie / Mithila Jugulam / Italian ryegrass (Lolium perenne L. ssp. multiflorum (Lam.) Husnot), one of the problem weeds of the US, evolved resistance to multiple herbicides including glyphosate due to selection in Arkansas (AR). Glyphosate is a 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibitor and amplification of EPSPS gene, the molecular target of glyphosate confers resistance to this herbicide in several weed species, including Italian ryegrass from AR. The objective of this study was to determine the expression of EPSPS gene and protein as well as distribution of EPSPS copies on the genome of glyphosate-resistant Italian ryegrass (ARR) using a known susceptible Italian ryegrass (ARS) from AR. EPSPS gene copies and expression of ARR and ARS were determined using quantitative PCR with appropriate endogenous controls. EPSPS protein expression was determined using Western blot analysis. Fluorescence in situ hybridization (FISH) was performed on somatic metaphase chromosomes to determine the location of EPSPS copies. Based on qPCR analysis, ARR plants showed a wide range of 12 to 118 EPSPS copies compared to a single copy in ARS. EPSPS gene expression correlated with the gene copy number in both ARR and ARS. Individuals with high EPSPS copies showed high protein expression in Western blot analysis. FISH analysis showed presence of brighter EPSPS signals, distributed randomly throughout the genome of ARR individuals compared to a faint signal in ARS plants. Random distribution of EPSPS copies was previously reported in glyphosate-resistant Palmer amaranth. Overall, the results of this study will help understand the origin and mechanism of EPSPS gene amplification in Italian ryegrass.

No description available.